Deprecate "grpc.ErrClientConnClosing"

CHANGELOG-3.4.md

@@ -125,6 +125,10 @@ See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0...v3.4.0) and
   - v3.5 will deprecate `etcd --debug` flag in favor of `etcd --log-level=debug`.
 - Change v3 `etcdctl snapshot` exit codes with [`snapshot` package](https://github.com/etcd-io/etcd/pull/9118/commits/df689f4280e1cce4b9d61300be13ca604d41670a).
   - Exit on error with exit code 1 (no more exit code 5 or 6 on `snapshot save/restore` commands).
+- Deprecated [`grpc.ErrClientConnClosing`](https://github.com/etcd-io/etcd/pull/10981).
+  - `clientv3` and `proxy/grpcproxy` now does not return `grpc.ErrClientConnClosing`.
+  - `grpc.ErrClientConnClosing` has been [deprecated in gRPC >= 1.10](https://github.com/grpc/grpc-go/pull/1854).
+  - Use `clientv3.IsConnCanceled(error)` or `google.golang.org/grpc/status.FromError(error)` instead.
 - Migrate dependency management tool from `glide` to [`golang/dep`](https://github.com/etcd-io/etcd/pull/9155).
   - <= 3.3 puts `vendor` directory under `cmd/vendor` directory to [prevent conflicting transitive dependencies](https://github.com/etcd-io/etcd/issues/4913).
   - 3.4 moves `cmd/vendor` directory to `vendor` at repository root.
@@ -449,6 +453,10 @@ Note: **v3.5 will deprecate `etcd --log-package-levels` flag for `capnslog`**; `
   - `PermitWithoutStream` is set to false by default.
 - Fix logic on [release lock key if cancelled](https://github.com/etcd-io/etcd/pull/10153) in `clientv3/concurrency` package.
 - Fix [`(*Client).Endpoints()` method race condition](https://github.com/etcd-io/etcd/pull/10595).
+- Deprecated [`grpc.ErrClientConnClosing`](https://github.com/etcd-io/etcd/pull/10981).
+  - `clientv3` and `proxy/grpcproxy` now does not return `grpc.ErrClientConnClosing`.
+  - `grpc.ErrClientConnClosing` has been [deprecated in gRPC >= 1.10](https://github.com/grpc/grpc-go/pull/1854).
+  - Use `clientv3.IsConnCanceled(error)` or `google.golang.org/grpc/status.FromError(error)` instead.
 
 ### etcdctl v3
 

Documentation/upgrades/upgrade_3_4.md

@@ -49,6 +49,29 @@ OK
 +etcd --peer-trusted-ca-file ca-peer.crt
 ```
 
+#### Deprecated `grpc.ErrClientConnClosing` error
+
+`grpc.ErrClientConnClosing` has been [deprecated in gRPC >= 1.10](https://github.com/grpc/grpc-go/pull/1854).
+
+```diff
+import (
++	"go.etcd.io/etcd/clientv3"
+
+	"google.golang.org/grpc"
++	"google.golang.org/grpc/codes"
++	"google.golang.org/grpc/status"
+)
+
+_, err := kvc.Get(ctx, "a")
+-if err == grpc.ErrClientConnClosing {
++if clientv3.IsConnCanceled(err) {
+
+// or
++s, ok := status.FromError(err)
++if ok {
++  if s.Code() == codes.Canceled
+```
+
 #### Deprecating `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metrics
 
 v3.4 promotes `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metrics to `etcd_mvcc_db_total_size_in_bytes`, in order to encourage etcd storage monitoring.

clientv3/client.go

@@ -587,10 +587,13 @@ func isUnavailableErr(ctx context.Context, err error) bool {
 	if err == nil {
 		return false
 	}
-	ev, _ := status.FromError(err)
-	// Unavailable codes mean the system will be right back.
-	// (e.g., can't connect, lost leader)
-	return ev.Code() == codes.Unavailable
+	ev, ok := status.FromError(err)
+	if ok {
+		// Unavailable codes mean the system will be right back.
+		// (e.g., can't connect, lost leader)
+		return ev.Code() == codes.Unavailable
+	}
+	return false
 }
 
 func toErr(ctx context.Context, err error) error {
@@ -610,9 +613,6 @@ func toErr(ctx context.Context, err error) error {
 			if ctx.Err() != nil {
 				err = ctx.Err()
 			}
-		case codes.Unavailable:
-		case codes.FailedPrecondition:
-			err = grpc.ErrClientConnClosing
 		}
 	}
 	return err
@@ -632,16 +632,19 @@ func IsConnCanceled(err error) bool {
 	if err == nil {
 		return false
 	}
-	// >= gRPC v1.10.x
+
+	// >= gRPC v1.23.x
 	s, ok := status.FromError(err)
 	if ok {
 		// connection is canceled or server has already closed the connection
 		return s.Code() == codes.Canceled || s.Message() == "transport is closing"
 	}
+
 	// >= gRPC v1.10.x
 	if err == context.Canceled {
 		return true
 	}
+
 	// <= gRPC v1.7.x returns 'errors.New("grpc: the client connection is closing")'
 	return strings.Contains(err.Error(), "grpc: the client connection is closing")
 }

clientv3/doc.go

@@ -90,7 +90,7 @@
 //		// with etcd clientv3 <= v3.3
 //		if err == context.Canceled {
 //			// grpc balancer calls 'Get' with an inflight client.Close
-//		} else if err == grpc.ErrClientConnClosing {
+//		} else if err == grpc.ErrClientConnClosing { // <= gRCP v1.7.x
 //			// grpc balancer calls 'Get' after client.Close.
 //		}
 //		// with etcd clientv3 >= v3.4

clientv3/integration/kv_test.go

@@ -463,7 +463,7 @@ func TestKVGetErrConnClosed(t *testing.T) {
 		defer close(donec)
 		_, err := cli.Get(context.TODO(), "foo")
 		if !clientv3.IsConnCanceled(err) {
-			t.Errorf("expected %v or %v, got %v", context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, got %v", context.Canceled, err)
 		}
 	}()
 
@@ -490,7 +490,7 @@ func TestKVNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Get(context.TODO(), "foo")
 		if !clientv3.IsConnCanceled(err) {
-			t.Errorf("expected %v or %v, got %v", context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, got %v", context.Canceled, err)
 		}
 		close(donec)
 	}()

clientv3/integration/lease_test.go

@@ -27,8 +27,6 @@ import (
 	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
 	"go.etcd.io/etcd/integration"
 	"go.etcd.io/etcd/pkg/testutil"
-
-	"google.golang.org/grpc"
 )
 
 func TestLeaseNotFoundError(t *testing.T) {
@@ -300,9 +298,8 @@ func TestLeaseGrantErrConnClosed(t *testing.T) {
 		defer close(donec)
 		_, err := cli.Grant(context.TODO(), 5)
 		if !clientv3.IsConnCanceled(err) {
-			// grpc.ErrClientConnClosing if grpc-go balancer calls 'Get' after client.Close.
 			// context.Canceled if grpc-go balancer calls 'Get' with an inflight client.Close.
-			t.Errorf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, or server unavailable, got %v", context.Canceled, err)
 		}
 	}()
 
@@ -372,7 +369,7 @@ func TestLeaseGrantNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Grant(context.TODO(), 5)
 		if !clientv3.IsConnCanceled(err) {
-			t.Errorf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v or server unavailable, got %v", context.Canceled, err)
 		}
 		close(donec)
 	}()
@@ -405,7 +402,7 @@ func TestLeaseRevokeNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Revoke(context.TODO(), leaseID)
 		if !clientv3.IsConnCanceled(err) {
-			t.Fatalf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Fatalf("expected %v or server unavailable, got %v", context.Canceled, err)
 		}
 		close(donec)
 	}()

functional/tester/stresser_key.go

@@ -176,9 +176,6 @@ func (s *keyStresser) isRetryableError(err error) bool {
 	case context.Canceled.Error():
 		// from stresser.Cancel method:
 		return false
-	case grpc.ErrClientConnClosing.Error():
-		// from stresser.Cancel method:
-		return false
 	}
 
 	if status.Convert(err).Code() == codes.Unavailable {

proxy/grpcproxy/adapter/chan_stream.go

@@ -18,7 +18,9 @@ import (
 	"context"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 // chanServerStream implements grpc.ServerStream with a chanStream
@@ -120,7 +122,7 @@ func (s *chanStream) RecvMsg(m interface{}) error {
 		select {
 		case msg, ok := <-s.recvc:
 			if !ok {
-				return grpc.ErrClientConnClosing
+				return status.Error(codes.Canceled, "the client connection is closing")
 			}
 			if err, ok := msg.(error); ok {
 				return err

proxy/grpcproxy/lease.go

@@ -26,7 +26,9 @@ import (
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 type leaseProxy struct {
@@ -214,7 +216,7 @@ func (lp *leaseProxy) LeaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) error
 	case <-lostLeaderC:
 		return rpctypes.ErrNoLeader
 	case <-lp.leader.disconnectNotify():
-		return grpc.ErrClientConnClosing
+		return status.Error(codes.Canceled, "the client connection is closing")
 	default:
 		if err != nil {
 			return err

proxy/grpcproxy/watch.go

@@ -23,8 +23,9 @@ import (
 	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
 
-	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 type watchProxy struct {
@@ -80,7 +81,7 @@ func (wp *watchProxy) Watch(stream pb.Watch_WatchServer) (err error) {
 		wp.mu.Unlock()
 		select {
 		case <-wp.leader.disconnectNotify():
-			return grpc.ErrClientConnClosing
+			return status.Error(codes.Canceled, "the client connection is closing")
 		default:
 			return wp.ctx.Err()
 		}
@@ -153,7 +154,7 @@ func (wp *watchProxy) Watch(stream pb.Watch_WatchServer) (err error) {
 	case <-lostLeaderC:
 		return rpctypes.ErrNoLeader
 	case <-wp.leader.disconnectNotify():
-		return grpc.ErrClientConnClosing
+		return status.Error(codes.Canceled, "the client connection is closing")
 	default:
 		return wps.ctx.Err()
 	}